Chapter 8Chapter 8

ITE 1Basic Networking

ITE 1Basic Networking

Networking BasicsNetworking Basics• Two Basic Types of Connections

Are:• WAN• Wide Area Network

• Think Modem - Long distances

• LAN• Local Area Network

• Think This Room

• Two Basic Types of Connections Are:• WAN• Wide Area Network

• Think Modem - Long distances

• LAN• Local Area Network

• Think This Room

Connection MediaConnection Media• Copper Cabling• Coax or UTP

• UTP is limited to 100 meters

• Fiber• Uses glass strands to carry pulses of light

• No electrical issues - Longer Distances

• Wireless• Radio signals or infrared

• Copper Cabling• Coax or UTP

• UTP is limited to 100 meters

• Fiber• Uses glass strands to carry pulses of light

• No electrical issues - Longer Distances

• Wireless• Radio signals or infrared

Connection MediaConnection Media

• UTP Cabling• Unshielded Twisted Pair• Uses Copper Wire• Number of twists and number of

conductors determine category number (Cat 3, Cat 5, Cat 6 etc.)

• UTP Cabling• Unshielded Twisted Pair• Uses Copper Wire• Number of twists and number of

conductors determine category number (Cat 3, Cat 5, Cat 6 etc.)

Oddball WAN MediaOddball WAN Media

• Power lines (PLC) can be used to carry both voice and data.

• It can actually provide higher bandwidth than phone lines (PSTN)

• Power lines (PLC) can be used to carry both voice and data.

• It can actually provide higher bandwidth than phone lines (PSTN)

Why Network?Why Network?

• Share files and resources• Lower Cost Software Licensing• Central Administration

• Share files and resources• Lower Cost Software Licensing• Central Administration

WLANWLAN

• Are wireless LAN’s• Can cover small or large areas.• Small area connections use shared

bandwidth.

• Are wireless LAN’s• Can cover small or large areas.• Small area connections use shared

bandwidth.

Network TypesNetwork Types• There are two basic types of networks• Peer to Peer

• All machines are equal• No central administration

• Client/Server Networks• Centrally administered• Lots of control and security, but increased

overhead• Easy data backup and centralized access to

data

• There are two basic types of networks• Peer to Peer

• All machines are equal• No central administration

• Client/Server Networks• Centrally administered• Lots of control and security, but increased

overhead• Easy data backup and centralized access to

data

BandwidthBandwidth

• Network speed is measured in Bandwidth

• Bps - Bits per second• Kbps - Kilobits per second• Mbps - Megabits per second

• Network speed is measured in Bandwidth

• Bps - Bits per second• Kbps - Kilobits per second• Mbps - Megabits per second

Communication Direction

Communication Direction

• Simplex• One way transmission

• Think Radio Station

• Half-Duplex• One Direction at a time

• Think Walkie Talkie

• Full-Duplex• Both directions at once

• Think telephone

• Simplex• One way transmission

• Think Radio Station

• Half-Duplex• One Direction at a time

• Think Walkie Talkie

• Full-Duplex• Both directions at once

• Think telephone

Network AddressingNetwork Addressing• Broken into three classes• Class A:• 1st Octet is a Network Address

• Class B:• 1st and 2nd Octets are Network Addresses

• Class C:• 1st, 2nd and 3rd Octets are used to

identify the network address

• Broken into three classes• Class A:• 1st Octet is a Network Address

• Class B:• 1st and 2nd Octets are Network Addresses

• Class C:• 1st, 2nd and 3rd Octets are used to

identify the network address

Network AddressingNetwork Addressing

• The remaining addresses are used for individual devices on each type of network.

• The remaining addresses are used for individual devices on each type of network.

Network AddressingNetwork Addressing

• Addressing can be done by the administrator and manually added to each machine or

• Done automatically through a process called DHCP where the address are handed out on a temporary basis

• Addressing can be done by the administrator and manually added to each machine or

• Done automatically through a process called DHCP where the address are handed out on a temporary basis

Network AddressingNetwork Addressing• Network Addressing has 3 Parts• IP Address - Must be unique for every machine on

the network• Subnet Mask - Should be the same for every

machine on the network• Tells the network which part of the IP is for the network

address and which part is for the individual devices

• Gateway - Tells the machine where to send the packets that go to the internet• Machines can communicate locally without the proper

gateway address.

• Network Addressing has 3 Parts• IP Address - Must be unique for every machine on

the network• Subnet Mask - Should be the same for every

machine on the network• Tells the network which part of the IP is for the network

address and which part is for the individual devices

• Gateway - Tells the machine where to send the packets that go to the internet• Machines can communicate locally without the proper

gateway address.

ProtocolsProtocols

• Protocols are a set of rules that govern communications• See page 8.3.4 for a list of

common protocols

• Protocols are a set of rules that govern communications• See page 8.3.4 for a list of

common protocols

ICMPICMP• Internet Control Message Protocol is

used to send messages between devices regarding network conditions

• One type of ICMP is called Packet Internet Groper or PING• It is used to test end to end connectivity

between devices• Tracert shows the whole route the

packets took along with timing.

• Internet Control Message Protocol is used to send messages between devices regarding network conditions

• One type of ICMP is called Packet Internet Groper or PING• It is used to test end to end connectivity

between devices• Tracert shows the whole route the

packets took along with timing.

How Information is SentHow Information is Sent

• Files are broken down into segments.

• The segments get headers and trailers added for addressing and error checking.

• This process is called Encapsulation.

• Files are broken down into segments.

• The segments get headers and trailers added for addressing and error checking.

• This process is called Encapsulation.

Network DevicesNetwork Devices

• Hubs• Hubs are “Dumb Devices” They are

really multi-port repeaters.• They simply send anything they receive

in any one port out all of their other ports.• They run at Half-Duplex only.• They extend the network without

breaking it into segments as switches and routers do.

• Hubs• Hubs are “Dumb Devices” They are

really multi-port repeaters.• They simply send anything they receive

in any one port out all of their other ports.• They run at Half-Duplex only.• They extend the network without

breaking it into segments as switches and routers do.

Network DevicesNetwork Devices

• Routers• Routers make forwarding

decisions based upon programming.• They are very smart devices and can

dynamically reroute packets as network conditions change.

• Routers• Routers make forwarding

decisions based upon programming.• They are very smart devices and can

dynamically reroute packets as network conditions change.

Network DevicesNetwork Devices• Switches• Switches and Bridges (Bridges are

single-port switches) are smarter than hubs.• They make forwarding decisions based

upon Mac (Hardware) Addresses• They are good because they block

unwanted traffic.

• Switches• Switches and Bridges (Bridges are

single-port switches) are smarter than hubs.• They make forwarding decisions based

upon Mac (Hardware) Addresses• They are good because they block

unwanted traffic.

Network TopographiesNetwork Topographies• Ethernet Standard (IEEE 802.3)

systems use a Star physical topology• But their logical topology is actually a

bus topology

• There are other types including a Mesh Topology where everything is connected to everything else and a Ring Topology which is just as it sounds.

• Ethernet Standard (IEEE 802.3) systems use a Star physical topology• But their logical topology is actually a

bus topology

• There are other types including a Mesh Topology where everything is connected to everything else and a Ring Topology which is just as it sounds.

Ethernet StandardsEthernet Standards

• Wireless Standard can be found on page 8.7.2

• One of the most common is 802.11g which runs at speeds up to 54 mps.

• Wireless Standard can be found on page 8.7.2

• One of the most common is 802.11g which runs at speeds up to 54 mps.

How LAN’s WorkHow LAN’s Work

• To avoid collisions where multiple devices try to talk at once:• Ethernet uses CSMA/CD• When a collision occurs all devices

back of a random amount of time, then listen to see if the coast is clear before resending

• To avoid collisions where multiple devices try to talk at once:• Ethernet uses CSMA/CD• When a collision occurs all devices

back of a random amount of time, then listen to see if the coast is clear before resending

ModelsModels• There are two models for explaining

how Networking is done.• One is TCP/IP• The other is the OSI Model

• See pages 8.8.3 for an explanation of the different models and how they relate to each other.

• There are two models for explaining how Networking is done.• One is TCP/IP• The other is the OSI Model

• See pages 8.8.3 for an explanation of the different models and how they relate to each other.

OSI ModelOSI Model• Explains how

things work.• Makes it so

equipment and software from different sources will work together.

• Explains how things work.

• Makes it so equipment and software from different sources will work together.

OSI ModelOSI Model• Data link

layer controls physical addressing otherwise known as the MAC address.

• Data link layer controls physical addressing otherwise known as the MAC address.

VoIPVoIP

• What is VoIP?• It’s voice (As in Telephone) over a

computer network. (Voice Over IP)• Advantage: It’s very cheap. Think

Vonage• Disadvantage: If your internet goes

down so does your phone service.

• What is VoIP?• It’s voice (As in Telephone) over a

computer network. (Voice Over IP)• Advantage: It’s very cheap. Think

Vonage• Disadvantage: If your internet goes

down so does your phone service.

Other Odd Ways of Connecting

Other Odd Ways of Connecting

• PLC• Carries Voice and Data Across

Power Lines• Requires no control wiring for

electrical devices at the customer’s end.

• Actually has more bandwidth than most other WAN technologies

• PLC• Carries Voice and Data Across

Power Lines• Requires no control wiring for

electrical devices at the customer’s end.

• Actually has more bandwidth than most other WAN technologies

Other Ways To ConnectOther Ways To Connect

• ADSL• Uses existing phone lines• Faster download (Downstream)

speeds than up upload (Upstream) speeds.• Limited distance from the phone

company switching center.

• ADSL• Uses existing phone lines• Faster download (Downstream)

speeds than up upload (Upstream) speeds.• Limited distance from the phone

company switching center.

Other Ways to ConnectOther Ways to Connect

• ISDN• Uses 2 phone lines - 3 Channels,

2B and one D.• Faster than dialup, but slower

than cable or DSL.• Expensive• Called BRI• Not used much anymore.

• ISDN• Uses 2 phone lines - 3 Channels,

2B and one D.• Faster than dialup, but slower

than cable or DSL.• Expensive• Called BRI• Not used much anymore.

That’s It!That’s It!

• Good luck on the test!• Good luck on the test!